MailScanner is a complete e-mail security system designed for use on
e-mail gateways. It protects against viruses, and detects attacks
against e-mail client packages (such as Outlook, Outlook Express,
Eudora). It can also detect almost all unsolicited commercial e-mail
(spam) passing through it and respond to all incidents in a wide variety
of ways.

Not only can it scan for known viruses, but it can also protect against
unknown viruses hidden inside e-mail attachments by refusing entry to
attachments whose filenames match any given pattern. This can include
generic patterns that trap filenames attempting to hide the true
filename extension (e.g. ".txt.vbs").

It is superior to many commercial packages in its ability to handle
attacks against itself, such as Denial Of Service attacks caused by
messages containing the "Zip of Death". It is easy to install into an
existing e-mail gateway, requiring very little knowledge of sendmail and
no change to an existing sendmail configuration.

MailScanner itself is entirely open source, but it uses widely known
commercial virus scanning packages at its core. The other software it
uses is all high quality open source software, leading to a system that
can be trusted for performance and reliability.

Optionally, unrar, unarj, and/or unace may be installed and MailScanner
will use them if they are installed.
